[PATCH] RPC: skip over transport-specific heads automatically Add a generic mechanism for skipping over transport-specific headers when constructing an RPC request. This removes another "xprt->stream" dependency. Test-plan: Write-intensive workload on a single mount point (try both UDP and TCP). Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- include/linux/sunrpc/msg_prot.h | 25 +++++++++++++++++++++++++ include/linux/sunrpc/xprt.h | 7 +++++++ net/sunrpc/auth_gss/auth_gss.c | 6 ++---- net/sunrpc/clnt.c | 5 ++--- net/sunrpc/xprtsock.c | 24 +++++++++++++++++------- 5 files changed, 53 insertions(+), 14 deletions(-) diff --git a/include/linux/sunrpc/msg_prot.h b/include/linux/sunrpc/msg_prot.h --- a/include/linux/sunrpc/msg_prot.h +++ b/include/linux/sunrpc/msg_prot.h @@ -76,5 +76,30 @@ enum rpc_auth_stat { #define RPC_MAXNETNAMELEN 256 +/* + * From RFC 1831: + * + * "A record is composed of one or more record fragments. A record + * fragment is a four-byte header followed by 0 to (2**31) - 1 bytes of + * fragment data. The bytes encode an unsigned binary number; as with + * XDR integers, the byte order is from highest to lowest. The number + * encodes two values -- a boolean which indicates whether the fragment + * is the last fragment of the record (bit value 1 implies the fragment + * is the last fragment) and a 31-bit unsigned binary value which is the + * length in bytes of the fragment's data. The boolean value is the + * highest-order bit of the header; the length is the 31 low-order bits. + * (Note that this record specification is NOT in XDR standard form!)" + * + * The Linux RPC client always sends its requests in a single record + * fragment, limiting the maximum payload size for stream transports to + * 2GB. + */ + +typedef u32 rpc_fraghdr; + +#define RPC_LAST_STREAM_FRAGMENT (1U << 31) +#define RPC_FRAGMENT_SIZE_MASK (~RPC_LAST_STREAM_FRAGMENT) +#define RPC_MAX_FRAGMENT_SIZE ((1U << 31) - 1) + #endif /* __KERNEL__ */ #endif /* _LINUX_SUNRPC_MSGPROT_H_ */ diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -155,6 +155,8 @@ struct rpc_xprt { size_t max_payload; /* largest RPC payload size, in bytes */ + unsigned int tsh_size; /* size of transport specific + header */ struct rpc_wait_queue sending; /* requests waiting to send */ struct rpc_wait_queue resend; /* requests waiting to resend */ @@ -236,6 +238,11 @@ int xprt_adjust_timeout(struct rpc_rqs void xprt_release(struct rpc_task *task); int xprt_destroy(struct rpc_xprt *xprt); +static inline u32 *xprt_skip_transport_header(struct rpc_xprt *xprt, u32 *p) +{ + return p + xprt->tsh_size; +} + /* * Transport switch helper functions */ diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -844,10 +844,8 @@ gss_marshal(struct rpc_task *task, u32 * /* We compute the checksum for the verifier over the xdr-encoded bytes * starting with the xid and ending at the end of the credential: */ - iov.iov_base = req->rq_snd_buf.head[0].iov_base; - if (task->tk_client->cl_xprt->stream) - /* See clnt.c:call_header() */ - iov.iov_base += 4; + iov.iov_base = xprt_skip_transport_header(task->tk_xprt, + req->rq_snd_buf.head[0].iov_base); iov.iov_len = (u8 *)p - (u8 *)iov.iov_base; xdr_buf_from_iov(&iov, &verf_buf); diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1075,13 +1075,12 @@ static u32 * call_header(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; - struct rpc_xprt *xprt = clnt->cl_xprt; struct rpc_rqst *req = task->tk_rqstp; u32 *p = req->rq_svec[0].iov_base; /* FIXME: check buffer size? */ - if (xprt->stream) - *p++ = 0; /* fill in later */ + + p = xprt_skip_transport_header(task->tk_xprt, p); *p++ = req->rq_xid; /* XID */ *p++ = htonl(RPC_CALL); /* CALL */ *p++ = htonl(RPC_VERSION); /* RPC version */ diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -282,6 +282,13 @@ static int xs_udp_send_request(struct rp return status; } +static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf) +{ + u32 reclen = buf->len - sizeof(rpc_fraghdr); + rpc_fraghdr *base = buf->head[0].iov_base; + *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen); +} + /** * xs_tcp_send_request - write an RPC request to a TCP socket * @task: address of RPC task that manages the state of an RPC request @@ -301,11 +308,9 @@ static int xs_tcp_send_request(struct rp struct rpc_rqst *req = task->tk_rqstp; struct rpc_xprt *xprt = req->rq_xprt; struct xdr_buf *xdr = &req->rq_snd_buf; - u32 *marker = req->rq_svec[0].iov_base; int status, retry = 0; - /* Write the record marker */ - *marker = htonl(0x80000000|(req->rq_slen-sizeof(*marker))); + xs_encode_tcp_record_marker(&req->rq_snd_buf); xs_pktdump("packet data:", req->rq_svec->iov_base, @@ -503,16 +508,19 @@ static inline void xs_tcp_read_fraghdr(s xprt->tcp_offset += used; if (used != len) return; + xprt->tcp_reclen = ntohl(xprt->tcp_recm); - if (xprt->tcp_reclen & 0x80000000) + if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT) xprt->tcp_flags |= XPRT_LAST_FRAG; else xprt->tcp_flags &= ~XPRT_LAST_FRAG; - xprt->tcp_reclen &= 0x7fffffff; + xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK; + xprt->tcp_flags &= ~XPRT_COPY_RECM; xprt->tcp_offset = 0; + /* Sanity check of the record length */ - if (xprt->tcp_reclen < 4) { + if (unlikely(xprt->tcp_reclen < 4)) { dprintk("RPC: invalid TCP record fragment length\n"); xprt_disconnect(xprt); return; @@ -1065,6 +1073,7 @@ int xs_setup_udp(struct rpc_xprt *xprt, xprt->prot = IPPROTO_UDP; xprt->port = XS_MAX_RESVPORT; + xprt->tsh_size = 0; xprt->stream = 0; xprt->nocong = 0; xprt->cwnd = RPC_INITCWND; @@ -1105,11 +1114,12 @@ int xs_setup_tcp(struct rpc_xprt *xprt, xprt->prot = IPPROTO_TCP; xprt->port = XS_MAX_RESVPORT; + xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32); xprt->stream = 1; xprt->nocong = 1; xprt->cwnd = RPC_MAXCWND(xprt); xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0; - xprt->max_payload = (1U << 31) - 1; + xprt->max_payload = RPC_MAX_FRAGMENT_SIZE; INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);